KIDA (for KInetic Database for Astrochemistry) is a project initiated by different communities in order to 1) improve the interaction between astrochemists and physico-chemists and 2) simplify the work of modeling the chemistry of astrophysical environments. Here astrophysical environments stand for the interstellar medium and planetary atmospheres. Both types of environments use similar chemical networks and the physico-chemists who work on the determination of reaction rate coefficients for both types of environment are the same.
For the interstellar medium, we provide chemical reactions occuring the gas-phase but also some parameters used to compute the interaction of species with the surface of interstellar grains and the chemical reactions occuring at the surface of these grains. We refer to Wakelam et al. (2010) and reference therein for a description of these processes. The types of data that are stored in KIDA are described here.
In KIDA, you can find different values for the same parameters from different bibliographic sources. In some cases, a quality indicator is also present. In addition to these reactions several chemical networks (a selection of reactions) specific for some astronomical objects are available. They can be directly from KIDA or compiled by users.

The current administrator of the database is Valentine Wakelam (Laboratoire d'Astrophysique de Bordeaux, France). Pierre Gratier (Laboratoire d'Astrophysique de Bordeaux, France works on the content of the database while Benjamin Pavone (Laboratoire d'Astrophysique de Bordeaux, France) is the web developer.
The experts in physics and chemistry who are working on the data present in KIDA are listed here.
If you have any comments or bug reports, please send an email to kida-obsu-bordeaux.fr.

You need to download templates in the csv format, fill out the file with your data and send it to us by email. For any addition of new channels or reactions, you need to add rate coefficients as well as a reference. Your data submitted to KIDA is sent to experts for validation.

« Not recommended » means that either we have found a mistake in the data or there is a more accurate value to use. We do not erease any value from KIDA, this is why we use this indicator. « Not rated » means that we do not know. « Valid » is used for data with a proper reference (usually papers published by physico-chemists). « Recommended » is used for reactions that have been studied by KIDA experts and a datasheet explaining the recommendation is also available.

If several data exist (from different groups for instance) for the same channel for the same or different ranges of temperature, they will all appear on the reaction page. On the seach result page, only the « best » value will appear.

kida.uva.xxx networks are a selection of gas-phase chemical reactions extracted from KIDA that can be directly used in astrochemical models for the interstellar medium. These networks are regularly updated. The current versions are:

Association reactions between two species (neutral or ionized) stabilized by the emission of a photon (A + B → AB + photon or A+ + B → AB+ + photon).

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Association of a neutral species and an anion, resulting in the ejection of the extra electron (A- + B → AB + e-).

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Recombination of a positive ion with an electron resulting in the dissociation of the molecule (AB+ + e- → A + B) or the emission of a photon (AB+ + e- → AB + photon) or the attachment of the electron (A + e- → A- + photon)

The broadening factor F is the factor by which the rate constant of a given recombination reaction at temperature T and at the reduced pressure Pr is reduced from the value it would have if recombination reactions behaved according to the Lindemann formula.
The reduced pressure Pr is compted by Pr =k0[M]/kinf with [M] the concentration of the third body.
k0 and k∞ are function of temperature computed with the Kooij formula. k0 is the low-pressure limiting form whereas kinf is the high-pressure limit. Both rate constants have the following unit: cm6.molecules-2.s-1.

In some cases, Fc can be calculated as a function of temperature from the Troe's fall-off parameters a, b, c, and d by:
a is dimensionless and b, c and d are in K (T as well of course).

When no specific Troe fall-off parameters can be retrieved from the literature, it can be assumed Fc = 0.64, following the simpler policy chosen by the NASA/JPL evaluation panel (Sander et al., 2006).
In KIDA, you will find Fc and the parameters to compute k0 and kinf.

To reproduce the surface chemistry on interstellar grains, we provide chemical reactions (i.e. reactants and products) with branching ratios, activation energies (when appropriate). For reactions with activation energies, the barrier can be overcome by tunneling, in that case, the width of the barrier is given. Explanations on who to treate the tunneling in chemical model scan be found here (TODO). Concerning parameters for the surface reactions and gas-grain interactions, the available data is very sparse. So as a start, we have put in the database what we have been using in our models. A BIG work on quality data have just started.

We classify the surface types into hierarchical categories (see classification below). Data providers can nevertheless provide data for other surfaces by describing the method necessary to reproduce these surfaces.

Photo-processes: Many information about the computation of the rates of photo-reactions can be found in Ewine van Dishoeck's web page at the University of Leiden (Netherlands): here.

The ISSI Team: To improve our knowledge on the kinetic of cold interstellar regions, we made a group of both astrophysicists and physico-chemists. Two meeting of this group in Bern (Switzerland) were funded in 2008 by the International Space Science Institute (http://www.issibern.ch/). The results of our discussions have been written in an article submitted to Space Science Reviews and can be downloaded here.